--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/services/MetaDataService.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,191 @@
+package org.dive4elements.river.artifacts.services;
+
+import org.w3c.dom.Document;
+
+import org.apache.log4j.Logger;
+
+import java.util.Map;
+import java.util.HashMap;
+
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallMeta;
+import org.dive4elements.artifacts.GlobalContext;
+import org.dive4elements.artifacts.ArtifactDatabase;
+import org.dive4elements.artifacts.ArtifactDatabaseException;
+
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+import org.dive4elements.artifacts.common.utils.StringUtils;
+
+import org.dive4elements.artifacts.common.ArtifactNamespaceContext;
+
+import org.dive4elements.river.artifacts.datacage.Recommendations;
+
+import org.dive4elements.river.artifacts.FLYSArtifact;
+
+
+/**
+ * Following XPaths are evaluated on the incoming document.
+ *
+ *  "/art:meta/art:artifact-id/@value" The UUID of the artifact. Optional.
+ *                                     Used to fill the template enviroment.
+ *  "/art:meta/art:user-id/@value"     The UUID of the user. Optional.
+ *                                     If given the user specific template is filled.
+ *  "/art:meta/art:outs/@value"        The list of outs used to recommend for the
+ *                                     various outputs.
+ *  "/art:meta/art:parameters/@value"  A list of key/value pairs to inject more
+ *                                     filters to the templating, as "key:value;key2:value2"
+ */
+public class MetaDataService
+extends      FLYSService
+{
+    private static Logger log = Logger.getLogger(MetaDataService.class);
+
+    public static final String XPATH_ARTIFACT_ID = "/art:meta/art:artifact-id/@value";
+    public static final String XPATH_USER_ID     = "/art:meta/art:user-id/@value";
+    public static final String XPATH_OUTS        = "/art:meta/art:outs/@value";
+    public static final String XPATH_PARAMETERS  = "/art:meta/art:parameters/@value";
+
+    /** The global context key of the artifact database. */
+    public static final String ARTIFACT_DATA_BASE_KEY =
+        "global.artifact.database";
+
+    public MetaDataService() {
+    }
+
+    @Override
+    protected Document doProcess(
+        Document      data,
+        GlobalContext globalContext,
+        CallMeta      callMeta
+    ) {
+        log.debug("MetaDataService.process");
+
+        String artifactId = XMLUtils.xpathString(
+            data, XPATH_ARTIFACT_ID, ArtifactNamespaceContext.INSTANCE);
+
+        if (artifactId != null
+        && (artifactId = artifactId.trim()).length() == 0) {
+            artifactId = null;
+        }
+
+        String userId = XMLUtils.xpathString(
+            data, XPATH_USER_ID, ArtifactNamespaceContext.INSTANCE);
+
+        if (userId != null
+        && (userId = userId.trim()).length() == 0) {
+            userId = null;
+        }
+
+        String outs = XMLUtils.xpathString(
+            data, XPATH_OUTS, ArtifactNamespaceContext.INSTANCE);
+
+        String parameters = XMLUtils.xpathString(
+            data, XPATH_PARAMETERS, ArtifactNamespaceContext.INSTANCE);
+
+        return doService(
+            artifactId, userId, outs, parameters, globalContext);
+    }
+
+
+    /**
+     * Split parameterstring in the form of key1:value1;key2:value2
+     * into hash (key1->value1, key2->value2).
+     * @param parameters "key1:value1;key2:value2"
+     * @param data Map into wich to put parameter hash and return.
+     * @return parameter data
+     */
+    protected static Map<String, Object> splitParameters(
+        String              parameters,
+        Map<String, Object> data
+    ) {
+        if (parameters != null) {
+            String [] parts = parameters.split("\\s*;\\s*");
+            for (String part: parts) {
+                String [] kv = part.split("\\s*:\\s*");
+                if (kv.length < 2 || (kv[0] = kv[0].trim()).length() == 0) {
+                    continue;
+                }
+                String [] values = kv[1].split("\\s*,\\s*");
+                data.put(kv[0], values.length == 1 ? values[0] : values);
+            }
+        }
+        return data;
+    }
+
+    /** Return the document containing matched stuff from meta-data.xml. */
+    protected Document doService(
+        String        artifactId,
+        String        userId,
+        String        outsString,
+        String        parameters,
+        GlobalContext globalContext
+    ) {
+        Document result = XMLUtils.newDocument();
+
+        FLYSArtifact flysArtifact;
+
+        if (log.isDebugEnabled()) {
+            log.debug("artifact  : " + artifactId);
+            log.debug("user      : " + userId);
+            log.debug("outs      : " + outsString);
+            log.debug("parameters: " + parameters);
+        }
+
+        if (userId != null && !StringUtils.checkUUID(userId)) {
+            log.warn("'" + userId + "' is not a UUID");
+            return result;
+        }
+
+        if (artifactId != null) {
+            if (!StringUtils.checkUUID(artifactId)) {
+                log.warn("'" + artifactId + "' is not a UUID");
+                return result;
+            }
+
+            Object dbObject =
+                (ArtifactDatabase)globalContext.get(ARTIFACT_DATA_BASE_KEY);
+
+            if (!(dbObject instanceof ArtifactDatabase)) {
+                log.error("Cannot find artifact database");
+                return result;
+            }
+
+            ArtifactDatabase db = (ArtifactDatabase)dbObject;
+
+            Artifact artifact;
+
+            try {
+                artifact = db.getRawArtifact(artifactId);
+            }
+            catch (ArtifactDatabaseException adbe) {
+                log.warn("fetching artifact failed", adbe);
+                return result;
+            }
+
+            if (!(artifact instanceof FLYSArtifact)) {
+                log.warn("artifact is not a FLYS artifact.");
+                return result;
+            }
+
+            flysArtifact = (FLYSArtifact)artifact;
+        }
+        else {
+            flysArtifact = null;
+        }
+
+
+        Map<String, Object> data = splitParameters(
+            parameters, new HashMap<String, Object>());
+
+        String [] outs = outsString == null
+            ? new String [0]
+            : outsString.split("\\s*,\\s*");
+
+        Recommendations rec = Recommendations.getInstance();
+        rec.recommend(
+            flysArtifact, userId, outs, data, result);
+
+        return result;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :